Chapman, who is serving a sentence of 20-years-to-life in New York's infamous Attica prison, is due to meet with a three-member parole board on August 9. It will be the sixth time he's attempted to gain release.

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Ono has repeatedly opposed Chapman's appeals and recently submitted a letter reiterating her stance to the parole board, according to her attorney, Peter Shukat.

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He would not confirm that it was the same letter that's reportedly been sent to the parole board every two years since 2000, the first time Chapman was eligible for parole.

That letter said in part that if Chapman was released, it would "...bring back the nightmare, the chaos and confusion once again. Myself and John's two sons would not feel safe for the rest of our lives."

Chapman is detained apart from the general population in a special unit at Attica, given his high-profile. He cleans offices and works in one of the libraries at the prison.

A representative the Correctional Association of America, a prisoners' rights group, doesn't think Chapman will be granted release, due to possible public backlash.

"Given that he committed a high profile crime and he killed one of the most famous and most beloved figures literally in the world, it's highly unlikely three parole commissioners would vote to grant him release," said Robert Gangi.